Transfer case puzzle

Hi guys, OK so out in the workshop tonight putting fluid in the transfer case after removal and complete drain. Supposed to hold 300ml on AWD tt model, I stopped at 400ml for fear of doing damage. Has anyone else encountered this? Did you just fill until a weep appears at fill point?

Yes to the bottom of the filler hole (1993 TT) I shall be doing my gearbox and transfer case in the next few days i hope and i’ll report .